Glacier change in Norway since the 1960s-an overview of mass balance, area, length and surface elevation changes

摘要

In this paper, we give an overview of changes in area, length, surface elevation and mass balance of glaciers in mainland Norway since the 1960s. Frontal advances have been recorded in all regions except the northernmost glaciers in Troms and Finnmark (Storsteinsfjellbreen, Lyngen and Langfjordjokelen). More than half of the observed glaciers, 27 of 49, had marked advances in the 1990s. The glaciological mass-balance values for the period 1962-2018, where 43 glaciers have been measured, show great inter-annual variability. The results reveal accelerated deficit since 2000, the most negative decade being 2001-2010. Some years with a positive mass balance (or less negative) after 2010s can be attributed to variations in large-scale atmospheric circulation. A surface elevation change and geodetic mass balance were calculated for a sample of 131 glaciers covering 817 km(2) in the '1960s' and 734 km(2) in the '2010s', giving an area reduction of 84 km(2), or 10%. The sample covers many of the largest glaciers in Norway, and they had an overall change in surface elevation of -15.5 m for the 50 year period. Converted to a geodetic mass balance this gives a mean mass balance of -0.27 +/- 0.05 m w.e. a(-1).